Governor valve



Sept. 17, 1946. a ARTW Em 2,407,791

GOVERNOR VALVE Filed. June 1,3942 2 Sheets-Sheet 2 lNVENTOR-S THOMAS E.MRRTI H Jorm F. names BY [2 7- 4 i/eir' ATToRNg Allh Patented Sept. 17,1946 UNETE. ST

2,407,791 GOVERNOR VALVE Thomas B. Martin and John F. Haines, Dayton,Ohio, assignors to General Motors Corporation, Detroit, Mich., acorporation of Delaware Application June 1, 1942, Serial No. 445,366

18 Claims. (01. 170 163) This invention relates to variable pitchpropellers, and particularly to those controlled by a fluid mediumconfined by a system of fluid connected passages within which the fluidmedium under pressure is selectively or automatically directed into anexpansion chamber for altering the effectiveness of a rotating propellerblade such as described and claimed in the U. S. patent to Blanchard eta1. 2,307,102 and on which this is an improvement.

An object of the invention is to provide a control valve and governingmechanism that will be instantaneously responsive to slight changes of acontrolling force.

Another object is to provide a governing mech anism that will besustained in a potentially responsive condition, such as to beimmediately available to respond to a weak controlling function incorrecting blade pitch setting upon slight variation from a selectedstandard of propeller operation.

Another object is to provide means for maintaining a control valve in astate of'constant vibratory motion of relatively small magnitudepreparatory to being moved to a force-deliveringposition immediatelythat a controlling function for correction from a condition of unbalanceis manifest.

Another object is to maintain a radially movable spring resisted controlvalve in a state of sustained oscillation so that the control valve willbe in readiness to effect a controlling function bearing a definiterelation to a change from a prescribed condition, directly that suchchange occurs.

Another object of the invention is the substantial elimination offriction effects in a control valve mechanism subject to small changesof controlling force, whereby the control valve will'be more readilyresponsive for correcting deviations from a predetermined standard ofoperating conditions.

A further object is to provide a governor mechanism for fluid circuitsthat is basically simple in design and easily of fabrication thoughefiicient and sensitive to changes in a controlling force at all speedsof operation and which makes use of a single spring force opposingcentrifugal force that gives stability by reason of a combination ofspring rate, columnar rigidity and geometrical relation of parts.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the ac-'companying drawings wherein a preferred embodiment of the presentinvention is clearly shown.

In the drawings Fig. l is a sectional view of a propeller mechanismfitted with a, fluid actuated regulator mechanism embodying the instantinvention, it being a view partly in section and partly in elevation,substantially as indicated by the line and arrows l-I of Fig. 2. r V

Fig; 2 is a transverse sectional view substantially as indicated by theline and arrows 22 of Fig. 1. i

Fig. 3 is a fragmentary showing on an enlarged scale illustratingcertain features of the invention, it being a view substantially asindicated by the line and arrows 3--3 of Fig. 2.

Fig. 4 is a similar fragmentary view in section showing a modified formvalve actuating lever.

With particular reference to the drawings, there is shownin Fig. 1, acontrollable pitch propeller havingblades i0 rotatably mounted insockets I2 radiating from a hub M, the blades having hollow rootportions l6 enclosing torque applying units I8 where they are anchoredin retained position by blade retaining nuts 20. The hub l4 extendsrearwardly to provide a sleeve 22 that seats on a rear cone 24 carriedby an engine driven shaft 26 extending from withi an engine nosing orcasing 28, there being splined connections 30 between the shaft andsleeve to provide the necessary driving couple. The hub is retained onthe shaft in the conventional manner by use of a forward cone and shaftnut, not herein shown. Afiixed to the forward end of the hub in anypreferred manner is a spinner adapter 32 that pilots the front end of aspinner 34 adapted to fair the hub and proximate portions of the blades,the spinner being notched appropriately at 35 for passage of the bladeroots in assembling. The rear end of thespinner is supported by abulk-head member or plate 38 of annular form and whose inner peripheryis secured beneath screw devices 40 threaded into the edge portion of aregulator 42.

The regulator is of annular form mounted for rotation with the hub l4,and comprises a plate member 44 having a central aperture making asliding fit over the sleeve portion 221 of the hub whererit is held infirm engagement by a sleeve nut 46. The plate'member 44 operates as asupport for fluid actuated control mechanism 7 and fluid connectionstherebetween as will presently appear, and provides one wall of areservoir enclosed by a cover member 52 fitting over the edge of theplate 44 where it is held by the screw devices before mentioned. Thecover member 42 extends radially inward to support an oil seal 54 thatengages the rear end of an adapter sleeve 55 extending into thereservoir along and in radially spaced relation with respect to thesleeve nut 46, the inner or forward end of the adapter sleeve engaging asecond oil seal 53 carried by the plate 44.

The adapter sleeve 56 is maintained against rotation with respect to theregulator by means of external support from the engine nosing 28, and isaccomplished by means of an abutting ring 60 engaging an adapter ring62, the two of which are circumferentially grooved to provide for a Wayto oscillatably receive a rin gear-64 meshing I with pinions 66 on theends of screw shafts 68 V journaled in the adapter sleeve 4%. Screwdevices (not shown) retain the elements 55, 60 and 52 in relativelynon-rotatable relation, and as an adapter assembly are retained againstrotation with respect to the regulator and hub by screw devices I0engaging the engine nosing 28. For oscillating the ring gear 84, it isprovided with an extension I2 to which may be connected a control cableor rod such as to be manipulated in the cockpit, "and makes it possibleto oscillate the ring gear 64 which rotates the screw shafts 68 andthereby moves anything that is appropriately connected with the ends ofthem extending within the reservoir 50. V

The fluidactuated control mechanism supported by the plate 44 includes apump or pressure developing means 1'4 mounted in a pocket or recess 16of the plate and adapted to have an intake 1'! from the reservoir 50,which pressure fluid is delivered to a pressure supply passage 18 inaccordance with the impetus given by a pump driving gear 80 provided bythe adapter sleeve 46, and meshing with a pump gear 82. Exposed to thepressure of the fluid in the pressure supply passage I8 thereris arelief valve 84 that determines the maximum of pressure that may bebuilt up Within the passage and adapted to spill any excess into the.reservoir 50 through a port 86. The terminal end of the pressure supplypassage 18 is at a juncture block 88 that forms a mounting pad for adistributing valve and governor mechanism 913. Also ending at themounting pad there are two control passages 92 and 94 each of whichleads from a port '96 and 98 respectively in the governor mechanism andcommunicate with opposite sides of the torque applying units Ill beforementioned. Similarly, the pressure supply passage '58 communicates witha port I00 of the governor mechanism and makes provision throughopration of the governor mechanism-to deliver fluid under pressure toeither side of the torque applying units. The governor mechanismresponds to predetermined operating conditions of the propeller to shiftfrom a position in which thecontrol passages are subject to equalpressures. to a position in which greater pressure is delivered to oneor the other of the ports 96 and 98 for correction with respect to aparticular setting on a scale.

The governor mechanism under .consideration comprises a valve block I 02having vmachined face I04 for mounting against the plate 44 over the pad88 by means of screw devices I06. Opening through the face IM there arethe ports 9-6, 98 and I00 before mentioned, and the inner extentsthereof are intersected 'by a bore I08 adapted to receive inpress-fitted or other sealed relation a porting sleeve I I0 so locatedas to extend radially of the axis of rotation for the propeller.

The inboard end of the porting sleeve I I 0 is provided with anoutwardly extending flange H2 adapted to engage the block I02 at the endof the bore Hi8 and prevent longitudinal movement thereof in response tocentrifugal force, while the other or outboard end of the sleeveprojects sufliciently beyond the block to receive a cross-pin I I4 forretaining the sleeve in place and for preventing rotation with respectto the block. Adapted for reciprocation within the sleeve there is avalve plunger IIS having a pair of longitudinally spaced lands H8 andI20 and adapted normally to register with ports in the porting sleeve H8that open into the ports 96 and 98. The ports in the sleeve ill! thatregister with the ports 98 and 93 are unique in their arrangement orlocation, in that they are arranged as sets or series, and for each portof the control passages a set comprises a circular row of small openingsI22 and a circular row of large openings I24 for the control port 95,with similar rows of small and large openings I26 and I28 respectivelyfor the control port 98. While the large openings in one row may bestaggered with respect to the small openings of the other and associatedrow, it is desirable that the small openings of each series he on theproximate sides of the respective series, and that the lineal extent ofthe series of openings be slightly greater than the longitudinaldimension of the cooperating land of the plunger valve. That particularrelation is shown generally in Fig. 4, where it appears that the landII8, though the valve is in the equilibrium position, does notcompletely cover both rows of openings E22 and I24. The same is truewith respect to the land I20 and the rows of openings I26 and I23.

The porting'sleeve Ilil also has openings I30 therethrough that operateto connect the port I from the pressure supply passage 18 to the spaceI32 within the porting sleeve IIU between the lands IE8 and I26. Thus.in a state of equilibrium oil or other fluid pressure medium is admittedto the three sets of openings in the porting sleeve, the center set ofopenings being exposed to the high pressure line from the pump andhaving no metering characteristics. Partially covering the other twosets of openings are the two lands of the plunger or distributor valveso as to have definite metering characteristics which give aproportionalizing characteristic to the governor by causing theeliective valve opening to hold a definite relationship to the amount ofcorrection to be made.

At the ends of the plunger valve II6 beyond the lands I I8 and I20 theporting sleeve is opened to the reservoir 50 such as to remove allrestriction to fluid flow relieving one of the control passages 9 2, 94when the other is being impressed with a fluid under pressure. As to theoutboard end of the valve, the return from the port 98 is through theopen end of the sleeve around the cross pin H4, and the inboard end isslotted at I34 through the flange II! and a portion of the V sleeve,through which the return from port 96 is had. To insure that this reliefis suflicient to take care of the return flow additional holes I36 maybe provided that open from the sleeve inboard 0f theland IIBthrough theside of the pivotally connectedby a cross-pin I42. In the form shown inFig.8, the lever I40 is of yoke construction in which a bridge portionI44 extends crosswise of the lever just outside of the block I02 and atits ends joins one end each of a pair of parallel arms I46'that extendlengthwise of the lever to engage a fulcrum roller I48; Extending fromthe bridge I44 in offset relation and between the arms I46 there is ashelf portion I50 whose one surface is socketed at I52 to seat the pointof a seating member I54 engaged by one end of a compression spring;I56.- In the form shown in Fig. 4, the lever I40 embodies somemodification and simplification as indicated by the reference character240, and comprises a single substantially straight lever extending fromthe valve member II6 into'the reservoir 50 to engage a single fulcrumroller I48. At an intermediate point of its length it supports a springseating member 254 engaged by one end of the spring I56. I

In either case, for supportin the other end of the spring I56 there isan arm I58 extending from the block I02 substantially parallel with thevalve actuating lever and which is apertured to receive the plain stemI60 of an adjustable plug I62 carrying a second spring seat I64. Thespring seat I64 is threaded upon the plug I62 and has an arm I66engaging in a slot $68 of the block I02 to prevent its turning relativeto the block. A stop collar I on the plug is notched at I12 forratcheting or detenting with a pin I13 in the arm I58, and a screwdriverslot I14 provides for selected adjustment of the spring I56. Since theportion I60 is capable of rotating and sliding in the hole of the armI58, a screwdriver applied to the slot I14 serves to push the stopcollar I10 away from the arm I58 and disengage one of the notches I12from the cooperating pin, after which the plug I62 may be turned untilthere is registration with some other notch. The force of the spring I56tends always to urge the stop collar I10 against the arm I58, and fromthat as a rigid support applies its force to the valve actuating arm Ior 240 as the case may be, tending to rock the am about its rollerfulcrum I48. I

That rocking of the arm, if it were not opposed by some other forcewould result in movement of the attached valve plunger II6 to a positioninboard of the equilibrium position shown in Fig. 4. That inboardposition is what is termed the under speed position and is that normallytaken when the propeller mechanism is at rest such as when the engine isnot operating. It is also the position of the valve when it is moved tocorrect the blade pitch adjustment for a drop in propeller speed. Anopposite extreme or outboard position is possible as will presentlyappear, and is termed the over speed position, which is the position ofthe valve when it is moved to correct the blade pitch adjustment for arise in propeller speed. The over speed position is due to centrifugalforce acting on the valve plunger II6 and 'associated lever, which isthe force that opposes the force of the spring I55 tending to rock thearm I40 or 240 about its respective fulcrum.

- With the fulcrum roller set in any normal position, as shown in Figs-3and 4, centrifugal force tends to throw the valve member II6 outwardlyor to the over speed position. That motion is resisted by the spring I56acting through the lever system. At equilibrium speed the moments aboutthe fulcrum roller of the spring force and the centrifugal force actingupon the valve member II6 are exactly equal and the valvemem-ber takes aneutral position, partially covering both sets of holes or openings .inthe porting sleeve. I Under those conditions no pres-1 5 sure fluidflows to the torque applying units or from them and the pitch of theblades :remains constant. An increase of speed above the equilibriumspeed will cause the centrifugal moment to be dominant and the governorvalve will move outwardly to the over speed position, opening thecontrol passage 94 to the high pressure fluid, and the control passage92 to the reservoir. In that position the fluid underpressure will flowfrom the pump to one side of the torque applying unit for increasing thepitch of the propeller blades. The increased pitch will cause the engineto slowdown and the slowing down of the engine will in turn bring thegovernor valve member I I6 back to its neutral position. Conversely, adrop in speed from the equilibrium speed will open the control passage92 to the high pressure fluid and the control passage 94 to thereservoir causing fluid under pressure to flow from the pump to theother side of the torque applying unit, thereby decreasing the pitch ofthe propeller blade until the governor valve is brought back to thenormal or equilibrium positionm t In order to control the equilibrium orgovernor speed, the roller fulcrum I48 may be moved fore and aft of thelever arm I40 or 240, thereby changing the equilibrium speed by changingthe ratio of the spring force arm to the centrifugal force arm. As theroller is moved toward the end of the lever the spring force becomesmore effective and more centrifugal force is required .to move the valvemember I I6 out to the equilibrium position. That movement isaccomplished by mounting the fulcrum roller or rollers I48 on a carriageI16 so that it may slide along on ways -I18 extending along side of thelever I40 or 240. The ways I18 may comprise the parallel arms of anotched plate I80 secured to the valve block I02 by screw devices I82,and the end of the arms should support a key or pin I84 to forestallseparation of the carriage therefrom. The carriages in both of the formsillustrated in Figs. 3 and 4 are the same except that for the single armcon,- struction of Fig. 4, it provides but one fulcrum roller I48, whilethat for the double arm con- 50 struction of Fig. 3 provides two fulcrumrollers, one for each of the arms I46. Attached to the carriage is ashoe I86 that rides in a groove I88 of a control ring I90 mounted formovement lengthwise of the adapter sleeve 56, which, as stated above, isa relatively fixed part of the propeller. Axial movement of this controlring is accomplished by the screw shafts 68 hereinbefore described, anddesirably there are three of them distributed about the circumference of,the adapter sleeve so that movement of the ring gear 64 rotates all ofthe screw shafts coincidentally.

From the foregoing it can be seen that each position of the controllever 12 corresponds to av deflnite equilibrium speed for the propellerThe screw shafts 68 may be sufiicient to prevent the contro1 ringfromrotating with respect to the relatively fixed parts of .the assembly,such as the adapter sleeve 56, but it is desirable to insure itsnon-rotation by means of a key or keys I82 7 or the like secured to theadapter sleeve 55 and received in sliding engagement by alnotch I04 cutin the inner surface of the control ring I80. By that construction, whenthe propeller is 1'0- tating, the regulator and all of thestructuralelements carried by;it rotateabout the adapter as;

for which regulation is to be made.

7 sembly secured to the engine nose and extending into the regulator.Thus, the adapter sleeve and control ring are held against rotation andthe governor mechanism is caused to revolve about them, the shoe I186riding in and following the course of the groove I88.

"The groove I88 in the control r n I9 is chined with a slight fore andaft wobble so that the governor-fulcrum. I48. oscillates fore a d aftduring each revolution of the propeller. The groove may zbcso formedthat it lies in a plane forming an angle with the plane of the controlring, such as to rovide a narrow fla 9 011 one side of the groove and awide flange i913 on the Opposite side, with reverse relations at one ormore points about the circumference of the control ring. Those featuresare shown in Fig. 3 of the drawings from which it should be apparentthat rotation of the regulator mechanism with respect to the controlring I90 causes a reciprocating or vibrating motion of the carriage I16for each rotation of the propeller. For that particular equilibriumsetting of the carriage, the arrowsa indicate the maximum length of thespring force arm or that obtaining while the ful- .crum roller I48 is inthe aft position of the oscillatory travel, while the arrows b indicatethe minimum length of the spring force arm or that obtaining while thefulcrum roller I48 is in the fore position of :said travel. Thedifference in length between the maximum .and minimum spring force armsthen represents the extent of the sustained incremental movementimparted to the carriage, and hence the fulcrum roller, due to thewobble of the control ring groove. The vibratory motion of the carriageneed not be great,

and desirably should not be great, but should be of such extent that thevalve member I I6, i responding to the continuous and reversinginfluences due to the aforementioned motion will be maintained insustained oscillation so as to be potentially responsive to an actualspeed change. Under those conditions, the control valve will be readilyresponsive to slight changes of a controlling force because of theelimination of static friction from the entire movable portion of thegovernor mechanism. The fulcrum roller 1.48 may be moved to a point m ror le distant from the point of spring force application in order toestablish a new equilibrium speed The selection of a new governing speedwill not, however, disturb or upset the oscillatory feature of theinstallation. It is of note that the motion of the valve piston is ofsuch rapidity that in oscil- V 'lating it does not operate to effect anyappreciable pitch shift. In effect then, when the valve is called uponto effect a regulating function it will have already been started on itsmovement toward either the under speed or over speed position, resultingin the requirement of less force and time in accomplishing the governingfunction.

Governor adjustment for maximum speed is obtained by adjusting thegovernor spring I56, access to which may be had by removing the fillerplug 200 in the cover 52 of the regulator housing. As hereinbeforedescribed, a slotted screw I14 is located inside the regulator cover,which has a bearing face I64 .in contact with the governor spring I56.By placing a screw driver in the slotted screw head and pushing thescrew in approximately q e inch to clear the locking pins, it ispossible to turn the screw. The governor spring pressure keeps the slotsl'lll engaged with the pins at all times, assuring a positive lock.Turning theadjusting screw I62 clockwise gives a decrease in R. P. M.,and turning it -counter-clocke wise gives an increase in R. P. M.Particular attention should be given to the spring I56. It should bemade accurately so that its columnar rigidity can be controlled throughthe ratio of Wire size to diameter. Particularly in the form ofconstruction shown in Fig. 4, stability at high speed is maintained bythe proper spring rate while stability at low speed is assisted by thecolumnar rigidity of the spring resistingthe til-t ing action of thegovernor lever. As an example of a suitable spring having the desiredcharacteristics use may be made of a spring having compressed force andrigidity in the order of 26 pounds when compressed to something likeonequanter inch less than its assembled'length as shown in the drawings.

From .the foregoing it is apparent that the regulator mechanism can beassembled as a single unit complete with all of the control mechanismmounted on the plate 44 and enclosed within the reservoir provided bythe plate 44 and the cover 52, rotatably engaging the adapter assemblyand particularly the sleeve 56 which completes the enclosure of thereservoir 50, thereby forming a complete unit. That unit so assembledmay be shipped separately as a replacement unit, or it may be installedimmediately on the propeller construction. In either case, the unit whenas sembled with the propeller is passed over the sleeve 22 where it isretained by'the sleeve nut 46 threading upon the sleeve 22. Theassembled hub and regulator is then mounted on the shaft 26 and pushedrearwardly until the adapter plate 62 can be anchored to the engine nose28 by means of one or more screw devices 10. Coincident with that, thehub sleeve 22 will seat against the rear cone 24 where it is held by theusual forward cone and shaft nut. If the reservoir 50 has nottheretofore been charged with the fluid operating medium it should noWbe done by rotating the propeller until the filler plug 200 is somethinglike 15 above the horizontal passing through the axis of rotation. Thefluid pressure medium, which might be a light oil, is now added until itreaches the level of the opening for the plug. Replacement of the plugand safetying, as should be done with all others of the screw devices,conditions the structure for immediate operation, though it is advisableto make tests and adjustments on the ground before actual .flight isattempted.

While there has been shown and described means for "accomplishing thevibratory motion of the fulcrum as embodying a groove disposed at anangle with the plane of rotation, the same result may be accomplished bymeans of a groove that wavers fore and aft of the plane of the ring 7carrying it. That is, the groove may be an undulating groove of regularor irregular track cut in the periphery of the ring so that the shoe infollowing it may cause reciprocation of the fulcrum and carriage foreach rotation of the de- In that way, the amount of vibration, or ratherthe amplitude of the vibratory movement would change as the fulcrum ismovedfore or aft of the :adapter sleeve, so that the greater amplitudewould be during the higher speed of propeller rotation.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood .that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. In anaircratt propeller, the combination of a cylindrical portingsleeve, a piston valve movable longitudinally relatively thereto, meansmounting the sleeve and valve for rotation with the propeller, meansincluding a balance of spring force and centrifugal force formaintaining the sleeve and valvein a relatively equilibrium position butadapted on domination by either spring force. or centrifugal force toeffect relative unidirectional movement of the valve and sleeve, andmeans operative upon rotation of the propeller effecting sustainedvibratory reciprocating movement of the valve and along the same path assaid unidirectional movement. 7 1

2. The combination of a "cylindrical porting sleeve," a piston valvemovable within and alon the "bore of said' sleeve in one direction inresponse to centrifugal force, means including a spring for opposingmovement of the valve by centrifugal force and:tending t move the valve'in the other direction to establish an equilibrium position of'thevalvewithin the sleeve, said valve adapted upon domination of eitheropposing force to move toward an extreme position within the sleeve toeffect a control function, means for rotatably mountingithefsleeve,valve and spring,

and mechanical means continuously acting upon said valve throughoutrotation of the assembly for effecting lineal vibration of the valvewithin the sleeve in thedirection ofmovement of the valve to a controlposition, whereby said valve is maintained continuously in a state ofreadiness to move to the control position directly that a controlfunction is manifest.

3. A governor control mechanism comprising a valve block h'avingpressure supply and control ports, a piston valve member slidable withinthe the valve member from the equilibrium position to a controllingposition in whichone of the control ports is connected withthe pressuresupply port, and cam means continuously operable upon rotation of thesupport means for effecting lineal vibration of the valve memberwithoutinterfering with the amount and the direction of its slidingmovement.

4. A governor control mechanism for a rotatable assembly comprising incombination, a valve block having .press'ure supply and control ports, avalve member. having lands adapted to cover the control ports of theblock and being of such massas to constitute a weight member respondingto centrifugal .force,means for rotatably mounting the block so that thevalve member .may move radially of the axis of rotation from anequilibrium positioning covering the control ports to either of twopositions connecting a con- ,trol 'port with the pressure supply port, alever pivotally connecting the valve member, rigid -members extendingfrom theblock and disposed 10 on, either side of the lever, a fulcrumcarried by one of the rigid members adapted to support the lever, andspring means engaging the lever and the other of the rigid members forbalancing the centrifugal force acting on the valve member while it isin the equilibrium position.

5. The combination set forth in claim 4, in which means are provided formoving th fulcrum along the rigid member toward and from the point ofspring engagement with the lever.

6. A governor control mechanism comprisin in combination, a valve blockhaving a longitudinal bore providing a pressure supply port intermediatea pair of control ports, a valve member movable along the bore of theblock and having lands adapted to cover the centrol ports, a leverpivotally connected to the valve member and extending to one side of theblock, rigid support means disposed on either and opposite sides of thelever, a movable fulcrum carried by one of the rigid supports engagingthe outer extent of the lever, yieldable means engaging an intermediateportion of the lever and the other of the rigid supports, rotatablemeans supporting the block and valve member so that the latter israclially disposed with respect to the axi of rotation, centrifugalforce tending to move the valve member from an equilibrium positionoutward to a controlling position, and said yieldab le means opposingthe centrifugal force to move the valve :in combination a valve chamberhaving spaced ports, a centrifugally responsive weight member comprisinga valve stem disposed within the chamber and controlling said ports byrelative reciprocation between said stem and chamber, means providing a,reservoir for enclosing the chamber and stem supplying a source ofoperating fluid therefor, means for rotating the reservoir therebyrevolving the chamber and stem, means extending into from without thereservoir for manually controlling the valve stem with respect to thechamber, and mean automatically operable upon rotation of said reservoirand including said extending means for vibrating the valve along itsreciprocating path, whereby to condition the valve stem for movement inresponse to small forces calling for a change of position of said valvestem.

8. A propeller control mechanism for use with a controllable bladepropeller having fluid actuated means for efiecting change in pitch ofthe blades, comprising in combination, a housing rotatable with thepropeller shaft, a relatively stationary member projecting into thehousing and cooperating therewith to form a reservoir, pump means withinthe housing and having an inlet from the reservoir, means for actuatingsaid pump means upon relative rotational movement between saidstationary member and said housing to provide a source of said fluidpressure, a regulator valve member within said housing responsive to thespeed of rotation for selectively 1 1 controlling the application ofsaid fluid pressure to said fluid actuated means to "effect change ofpitch of the propeller blades, means outside of the housing andprojecting into the reservoir for selecting the speed of rotation atwhich the regulator valve member will effect a change in pitch, andmeans including a part of the stationary member effecting linealvibration of the regu- I lator valve member within the housingsuflicient to overcome static friction to movement 50 that small changesin speed of rotation of the propeller will be responded to by theregulator valve member for connecting the pump developed pressure withthe fluid actuated means.

9. A propeller control mechanism for use with an adjustable bladepropeller having fluid actuated means for effecting change in the pitchof the blades, comprising in combination, a source of fluid pressure, aregulator valve body mounted for rotation with said propeller anddirectly responsive to centrifugal force, means for supplying thepressure fluid under the control of said regulator valve to said fluidactuated means, resilient means acting radially with a forcesubstantially independent of the speed of said propeller for opposingthe action of centrifugal force on said body with a predeterminedregulating force, a lever for applying the force of said opposingmeansto be effective upon said valve body, an adjustable control operablefrom the exterior of said rotatin propeller for varying theefiectivemoment arm of said lever, and meansconstantly acting upon said lever forvibrating said regulator valve along the path of .movement effected bythe centrifugal force and opposing .means, said vibration conditioningthe regulator valve .for movement in response to slight disturbances ofequilibrium between centrifugal and opposing forces. 7

10. The combination set forth in claim 9, wherein the adjustable controlincludes a con trolring and a plurality of spaced high lead controlscrews with means for coincidentally rotating the control screws, saidcontrol ring providing a groove therein with fore and aft pointsdisposed on opposite sides of the plane of the ring, and means includinga fulcrum supporting one end of the lever and following the groove ofthe ring for vibrating the regulator valve along the path of movementeffected by the centrifugal force and opposing means thereby minimizingstatic friction of the valve member against movement by a controlfunction.

11. In a controllable pitch propeller, a regulator mechanism comprisingin combination, a governor valve assembly carriedfby the propeller andrevolvable about a relatively fixed part, said assembly including avalve block having spaced ports opening into a radially extending bore,a valve stem being itself directly responsive to centrifugal force andsubject to generally radial movement along the bore of said block, alever pivoted to thevalve stem and extending substantially at rightangles to said radially extending bore, a movable fulcrum interposedbetween the lever and said fixed Dartfor supporting the end of thelever, means exerting a substantially constant spring force bearing uponan intermediate portion. of the lever and opposing movement of the valvestem by centrifugal force, said spring force and centrifugal force ata'predetermined ,speed of pro eller rotation maintaining the valve stemin equilibrium position with respect to the spaced ports, means carriedby the relatively fixed part for moving the fulcrum for determining thespeed at which the equilibrium position shall obtain, and means forimpressing upon'said fulcrum during rotation of thepropeller'reciprocating movement of short amplitude along the lever forvibrating the valve stem lineally of the path of control movement. e l

12. The combination set forth in claim 11, wherein the means for movingthe fulcrum for speed determination constitutesa control ring slidableaxially of the fixed part and which 'control ring has a movable'groove"within which rides a shoe for effecting reciprocatory movement of thefulcrum. r

13. The combination set forth in .claim ll, wherein the means for movingthe fulcrum constitutes a control ring" slidable along the fixed partand has a groove within whichrides ae'shoe carried by the fulcrum, saidgroove lying :in a plane forming an angle with the plane of rotation,whereby said fulcrum 'is reciprocated for each revolution of thepropeller; 1

14. In a controllable pitch propeller, a regulator valve stem being"itself directly responsive to centrifugal force and subject togenerally radial movement along the bore of said block, a;1ever operableupon the valvestem and extending sub-' stantially parallel with the axisof rotation for the propeller, a movable fulcrum interposed between thelever and the fixed part for supporting the end of the lever, meansexerting asubstantially constant yielding force bearing upon the leverat a point intermediate itslength and opposing movement of the lever bycentrifugal force, said yielding force and centrifugal force at apreselected speed of propeller rotation maintaining the valve stem inequilibrium position with respect to the spaced ports, means provided bythe relatively fixed part for moving the fulcrum for preselecting thespeed at which the equilibrium position shall obtain, and mean forimpressing upon said fulcrum in response to rotation of the propellerlineal vibratory movement of 'shor amplitude along the length of thelever. c

15. The combination set forth in claim .14, in which the means formoving the fulcrum constitutes a control ring slidable along the fixedpart and has a groove within which'rides a shoe'carried by the fulcrum,said groove lying in a plane forming an angle with'the plane of saidcontrol ring, whereby said fulcrum is reciprdcated during each rotationof the propeller.

16. The combination set forth in claim 14, in-

which the means for moving the fulcrum constitutes a control ringslidable along the fixed part and has a camming groove in its peripherywithin which rides a shoe carried by the fulcrum, whereby rotation ofthe propeller mechanism about the fixed part causes vibratory movementof the fulcrum along the length of the lever.

17. The combination set forth in claim 9 wherein the adjustable controlincludes a grooved control ring and high lead screws operable from aremote point for moving the control ring along the length of the lever,said high lead screws maintaining the groove of said ring with spacedpoints fore and aft of the plane of the ring where by the fulcrum infollowing the groove effects vibratory movement of the valve memberdurin rotation of the propeller.

18. In a rotatable hydraulic regulator for air- 13 craft propellers, thecombination comprising, a plate providing a conduit system-mounted forrotation by the propeller, a fixed tubular extension ending near theplate, a control valv including a porting sleeve open to the conduitsystem, and a plunger mounted on the plate for rotation therewith, saidplunger itself being a weight member responding to centrifugal force ofpropeller rotation for controlling the flow of fluid 14 in the conduitsystem, means carried by the tubular extension for controlling theaction of the plunger and including a grooved ring movable axially ofthe extension, and means including the control ring for rapidlyreciprocating the plunger throughout rotation of the plate relative tothe extension.

THOMAS E. MARTIN.

JOHN F. HAINES.

